I see every time I unplug from an external monitor, and sometimes when unsleeping my computer, that the size of each pane in my split windows is jumping between two sizes. This will cause the CPU to start to wind up and my fan to turn on. To stop it, I can manually resize the window a little and it will behave normally again and everything settles down on the CPU front. I've attached a video showing what happens.
video of bug happening

This is very consistent, and I'll grab a debug log on Monday when I have a monitor to use to reproduce it on.